U.S. patent application number 12/997311 was filed with the patent office on 2011-06-16 for input/output connector with capacitive coupling mating interface.
This patent application is currently assigned to MOLEX INCORPORATED. Invention is credited to Toshihiro Niitsu.
Application Number | 20110143602 12/997311 |
Document ID | / |
Family ID | 40757037 |
Filed Date | 2011-06-16 |
United States Patent
Application |
20110143602 |
Kind Code |
A1 |
Niitsu; Toshihiro |
June 16, 2011 |
INPUT/OUTPUT CONNECTOR WITH CAPACITIVE COUPLING MATING
INTERFACE
Abstract
A plug connector (100) has an insulative housing (103) with an.
elongated mating blade (104) that supports a plurality of
conductors (130) in the form of conductive surfaces disposed on a
mating face of the mating blade. Dielectric barriers (150) are
disposed on the conductive surfaces so that galvanic connection
with contacts on a circuit board is prevented. The dielectric
barriers permit transfer of electrical signals from the plug
connector conductors to the circuit board contacts. The plug
connector fits into a shell member (200) mounted to the circuit
board (153) and the shell member includes a plurality of
cantilevered press arms (220) that apply a contact pressure on the
plug connector to ensure contact between the dielectric barriers
and the circuit board contacts.
Inventors: |
Niitsu; Toshihiro; (Tokyo,
JP) |
Assignee: |
MOLEX INCORPORATED
|
Family ID: |
40757037 |
Appl. No.: |
12/997311 |
Filed: |
April 28, 2009 |
PCT Filed: |
April 28, 2009 |
PCT NO: |
PCT/US09/41917 |
371 Date: |
February 25, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61131525 |
Jun 10, 2008 |
|
|
|
Current U.S.
Class: |
439/660 |
Current CPC
Class: |
H05K 3/32 20130101; H05K
2201/10189 20130101; H05K 2201/10446 20130101; H05K 1/0239
20130101 |
Class at
Publication: |
439/660 |
International
Class: |
H01R 24/00 20110101
H01R024/00 |
Claims
1. A connector assembly for providing a capacitively coupled
connection between a plurality of wires and a plurality of planar
contact disposed on a circuit board, comprising: a hollow shell for
mounting to the circuit board, the shell including a plurality of
walls, including at least two opposing side walls and a top wall
interconnecting the two sidewalls together, the walls cooperatively
defining a hollow interior receptacle that encloses the circuit
board contacts and which receives a portion of an opposing mating
connector; a plug connector insertable into said shell, the plug
connector including an insulative housing, a mating blade extending
outwardly from the housing, the mating blade including a mating
surface and an opposing pressure surface, the mating surface
including a plurality of conductive planar contact surfaces
disposed thereon and spaced apart from each other widthwise of said
mating surface, the mating blade contact surfaces being dimensioned
so as to lie in one-to-one opposition to said circuit board
contacts when said plug connector is fully inserted into said
shell, said plug connector further including a dielectric barrier
disposed on each of said mating blade contact surfaces so as to
prevent galvanic contact between said plug connector contact
surfaces and said circuit board contact pads when said plug
connector is fully inserted into said shell, the dielectric
barriers cooperatively providing a dielectric interface that
permits capacitive coupling between said mating blade contact
surfaces and said circuit board contact pads when said plug
connector is fully inserted into said shell; wherein said shell
further including means for exerting pressure on said mating blade
pressure surface to force said mating blade dielectric barriers
into contact with said circuit board contact pads.
2. The connector assembly of claim 1, wherein said pressure
exerting means includes at least one press arm formed integrally
with said shell top wall.
3. The connector assembly of claim 1, further including at least a
pair of conductive surfaces disposed on said mating blade mating
surface and said pressure exerting means includes at least two
press arms that extend the interior receptacle and into contact
with said mating blade pressure surface, the pair of conductive
surfaces being spaced apart from each other widthwise along said
mating surface.
4. The connector assembly of claim 1, wherein said shell includes a
pair of mounting flanges extending from said side walls, the
mounting flanges being arranged to mate with mounting surfaces on
said circuit board.
5. The connector assembly of claim 6, wherein said shell is formed
of a conductive material.
6. The connector assembly of claim 3, wherein said press arms are
spaced apart from each other widthwise along said shell top
wall
7. The connector assembly of claim 1, wherein said shell includes a
pair of engagement flanges extending inwardly from said two side
walls, the engagement flanges engaging said plug connector mating
blade when said plug connector is fully inserted into said
shell.
8. The connector assembly of claim 7, wherein said plug connector
mating blades includes a pair of notches disposed on two opposing
sides thereof, the notches receiving said engagement flanges when
said plug connector is fully inserted into said shell.
9. The connector assembly of claim 8, wherein said notches are
disposed on said mating blade adjacent said housing.
10. The connector assembly of claim 1, wherein said dielectric
barrier has a dielectric constant of at least 300.
12. The connector assembly of claim 1, wherein said dielectric
barrier has a thickness which is less than a corresponding
thickness of said conductive surface onto which said dielectric
barrier is applied.
13. The connector assembly of claim 12, wherein said dielectric
barrier has a thickness than is between about 0.0003 millimeters to
0.2 millimeters thick.
14. The connector assembly of claim 1, wherein said shell member
has a height of about 1.60 millimeters or less.
15. A male connector for establishing an electrical connection
between a plurality of wires and a plurality of contacts by way of
a capacitively coupled mating interface, comprising: an insulative
connector housing, the connector housing including an elongated
mating blade extending from said connector housing, the mating
blade including two opposing faces, one of the two faces defining a
contact face and the other of said two surfaces defining a pressure
face upon which a pressure force may be exerted, the contact face
including a plurality of planar, conductive surfaces extending in a
lengthwise direction along said contact face, the conductive
surfaces being spaced apart from each other in a widthwise
direction upon said contact face, the connector further including a
dielectric barrier disposed on said conductive faces which provides
a non-conductive member interposed between said conductive surfaces
an opposing conductive surfaces of a mating connector or circuit
board; said connector housing further including a plurality of
termination nests for receiving a conductor of an electrical wire,
each termination nest being connected one of said conductive
surfaces.
16. The connector of claim 15, wherein said conductive surfaces are
plated on said mating blade and said dielectric barriers have a
thickness that does not exceed 20,000 nanometers
17. The connector of claim 15, wherein said connector housing
includes a pair of wing portions extending widthwise from said
mating blade, the wing portions defining the respective notches on
opposite sides of said shell member.
18. A connector assembly for providing a capacitively coupled
connection between a plurality of wires and a plurality of planar
contact disposed on a circuit board, the connector assembly,
comprising: a hollow shell for mounting to the circuit board, the
shell including a plurality of walls, including at least two
opposing side walls and a top wall interconnecting the two
sidewalls together, a bottom wall also interconnecting said two
side walls together, the walls all cooperatively defining a hollow
interior receptacle for mounting to the circuit board contacts and
which receives a portion of an opposing mating connector; a plug
connector insertable into said shell, the plug connector including
an insulative housing, a mating blade extending outwardly from the
housing, the mating blade including a mating surface and an
opposing pressure surface, the mating surface including a plurality
of conductive planar contact surfaces disposed thereon and spaced
apart from each other widthwise of said mating surface, the mating
blade contact surfaces being dimensioned so as to lie in one-to-one
opposition to said circuit board contacts when said plug connector
is fully inserted into said shell, said plug connector further
including a dielectric barrier disposed on each of said mating
blade contact surfaces so as to prevent galvanic contact between
said plug connector contact surfaces and said circuit board contact
pads when said plug connector is fully inserted into said shell,
the dielectric barriers cooperatively providing a dielectric
interface that permits capacitive coupling between said mating
blade contact surfaces and said circuit board contact pads when
said plug connector is fully inserted into said shell; and, said
shell bottom wall including top and bottom surfaces, said bottom
wall being formed from a non-conductive, dielectric material, the
shell member bottom wall top surface including a plurality of
conductive surfaces disposed thereon and the shell member bottom
wall bottom surface including a plurality of conductive surfaces
disposed thereon and in alignment with said shell member bottom
wall top surface conductive surfaces so as to transfer electrical
signals received from said plug connector through said shell member
bottom wall between said shell member bottom wall top and bottom
conductive surfaces by way of capacitively coupling.
19. The connector assembly of claim 18, wherein said shell member
further includes means for exerting pressure on said mating blade
to force said mating blade dielectric barriers into contact with
said circuit board contact pads.
Description
BACKGROUND OF THE INVENTION
[0001] The Present Invention is generally directed to input-output
("I/O") connectors, and more particularly to I/O connectors that
utilize capacitive-coupling conductor structures to obtain a
significant reduced overall height.
[0002] I/O connectors are used in many electronic applications. One
such application is in mobile telephones. The industry seeks to
reduce the overall size of these telephones and I/O connectors can
be a barrier to reductions in height as I/O connectors, in many
applications, typically require two rows of terminals, one above
the other. These multiple rows increase the height of the connector
and the manner in which the end or tail portions of the terminals
must be arranged, increases the overall size of the connector,
which makes their usage in mobile telephones impractical in view of
the desire in the mobile telephone industry toward reduced
size.
[0003] Accordingly, the Present Invention is directed to an
improved I/O connector that overcomes the aforementioned
disadvantages and presents reduced height, size and cost
opportunities.
SUMMARY OF THE INVENTION
[0004] It is a general object of the Present Invention to provide
an improved I/O connector of reduced height and size which utilizes
capacitive coupling to effect signal transmission between the
connector and contacts of a circuit board.
[0005] Another object of the Present Invention is to provide a
plug-style I/O connector wherein the plug connector has an
insulative housing with a mating blade extending therefrom, the
mating blade supporting a plurality of conductive contacts, the
contacts including a dielectric layer, or film applied thereto so
as to permit the mating blade to be positioned such that the
contacts and dielectric film on the mating blade are positioned in
opposition to a like arrangement of contacts arranged on a circuit
board, the dielectric layer providing a barrier to galvanic contact
between the contacts of the circuit board and the connector.
[0006] Yet another object of the Present Invention is to provide an
I/O connector that utilizes capacitive coupling arrangement for
signal transmission, the connector including a housing for
supporting a plurality of wires thereon, a mating blade for
contacting with an opposing set of contacts disposed on a circuit
board, the mating blade including a plurality of conductive
surfaces spaced apart from each other, the conductive surfaces
having generally planar surfaces extending along the mating blade,
a dielectric film or coating disposed on the exterior of the
conductive surfaces, the mating blade further including at least
one reaction surface disposed thereon in opposition to the
conductive surfaces thereof for providing a dielectric transmission
media interposed between the contacts of the I/O connector and the
contact of the circuit board, the connector having a reduced height
compared to other I/O connectors.
[0007] It is still another object of the Present Invention to
provide an I/O connector of the plug style as described immediately
hereinabove, along with a guide member in the form of a hollow
shell that is mountable to the circuit board, the shell including a
plurality of walls that cooperatively define a hollow interior
receptacle, the receptacle having an opening disposed in a bottom
wall thereof so that when the receptacle is properly oriented on a
circuit board, a plurality of conductive contact pads arranged on
the circuit board are exposed within the receptacle, so that the
I/O connector combined conductive surfaces and dielectric film may
be slid thereover and in opposition therewith, the shell further
including means for applying a force to the I/O connector mating
blade pushing the blade in opposition to the circuit board
contacts.
[0008] In yet a further object of the Present Invention is to
provide the shell with at least one press member for exerting a
force, preferably a downward force, upon the I/O connector mating
blade, the shell further including one or more engagement members
that serve to orient the plug connector in alignment with the
circuit board for mating with the contact pads disposed on the
circuit board.
[0009] It is a still further object of the Present Invention to
provide a pair of press members, in the form of cantilevered arms
integrally formed with the shell, the press arms being formed in a
top wall of the shell by U-shaped openings stamped in the shell and
the press arms being bent downwardly into the interior receptacle
of the shell, the arms frictionally engaging an opposing upper
surface of the I/O connector body, and the arms exerting a downward
force on the plug connector so that the dielectric film applied to
the plug connector contacts is placed into contact with the
contacts on the circuit board.
[0010] The Present Invention accomplishes the above and other
objects by way of its unique structure. In accordance with a first
embodiment of the Present Invention, an improved I/O connector is
provided in the form of a plug connector with an insulative
connector housing, or body portion. This housing has two opposing
surfaces and one of the two surfaces is used as a mating portion of
the connector and the other of the two surfaces is used as a
terminating portion of the connector. Typically, the connectors of
the Present Invention will be used to connect a plurality of wires,
to traces on a circuit board. In this regard, the connector housing
terminating face may be provided with a plurality of individual
supports, taking the form of slots in the first embodiment for
receiving exposed conductors of the wires which are attached to
conductors of the connector housing by way of soldering or the
like.
[0011] The mating surface of the plug connector has a plurality of
conductors disposed thereon and preferably these conductors take
the form of planar portions or members that extend lengthwise along
the mating surface and which are spaced apart from each other
widthwise of the connector housing. The conductors may be
conventional metal terminals, or they may include coated surfaces
of the connector housing, such as a conductive plating, a
conductive plastic or a sputtered metal application as well as
other means. These conductors are connected to the wires by way of
interposed conductive paths.
[0012] Importantly, the conductors are planar and preferably smooth
in their lengthwise extent along the connector housing mating face.
In order to utilize the conductors in a capacitive coupling, a
dielectric is applied to the exposed surfaces of the conductors,
that is, to the surfaces that are in opposition to the conductive
surfaces on the circuit board when the plug connector is mated to
its receptacle shell. This dielectric may be a discrete member and
if so, it is preferably provided in the form of a thin film, or
layer, applied directly to the conductive surfaces of the
conductors. Alternatively, the dielectric may be provided as a
coating on the conductive surfaces, and sputtering is one type of
application that has been found to give good results.
[0013] An exterior shell is also provided as part of the connector
assembly and this shell serves the purpose of pressing down on the
connector to force it into contact with the surface of the circuit
board. In order to effect proper capacitive coupling, it is
desirable to have the two conductors (connector and circuit board)
the same size and to avoid the presence of any air gaps between the
dielectric member and the conductors. This is accomplished by
integrating a pressing means with the shell. The shell has a top
wall which opposes the top surface of the plug connector when the
plug connector is inserted into the shell. One or more pressure
members is formed as part of the shell and in the preferred
embodiment, these pressure members may take the form of arms that
are bent downwardly into the receptacle at an angle so that they
will interferingly contact the top surface of the plug connector.
These pressure members exert a required downward force on the plug
connector and generate enough downward pressure to substantially
eliminate any significant air gaps between the dielectric members
and the contacts on the circuit board which oppose them.
Preferable, the pressure members include a pair of arms that are
cut into the top wall of the shell and which are spaced apart
widthwise of the shell so that they contact the plug connector
housing above at least two of the conductive surfaces thereof.
[0014] The press arms of the shell serve to press the plug
connector down into contact with the circuit board contact pads and
the shell may further include one or more engagement members formed
therewith that provide a means for locating, or orienting, the plug
connector within the shell and in alignment with the circuit board
contacts. These means may include a pair of inturned edges, or
retention tabs, that are disposed near the rear of the front edge
of the shell. The plug connector has corresponding notches formed
along its side that receive these retention tabs so that the
conductors of the plug connector are oriented and aligned with the
contact pads on the circuit board, and the plug connector is held
in place within the shell.
[0015] In another embodiment of the Present Invention, the shell
includes a bottom wall that extends between its two side walls and
the bottom wall further includes one or more contacts formed in or
disposed on the bottom wall. The bottom wall is formed of a
non-conductive, material so that the contacts formed thereon may be
easily isolated from each other by distance. The contacts may be
formed as planar coatings on the bottom surface of the bottom wall
of the shell member. The shell member bottom wall may be formed of
the dielectric material and thus the bottom wall of the shell
member is used in this embodiment as the dielectric barrier.
Alternatively, the contacts may also be formed separately in the
shell member bottom wall with insulative portions separating them
widthwise so that the dielectric barrier can remain upon the plug
conductor contact surfaces. The contacts, in this alternate
embodiment, are preferably raised to a level above the bottom wall
so as to better facilitate direct contact with them by the
dielectric members of the plug connector. The contacts preferably
extend through the body of the shell so that they may be directly
attached to the circuit board, if desired.
[0016] These and other objects, features and advantages of the
Present Invention will be clearly understood through a
consideration of the following detailed description.
BRIEF DESCRIPTION OF THE FIGURES
[0017] The organization and manner of the structure and operation
of the Present Invention, together with further objects and
advantages thereof, may best be understood by reference to the
following Detailed Description, taken in connection with the
accompanying Figures, wherein like reference numerals identify like
elements, and in which:
[0018] FIG. 1 is a perspective view of an input-output (I/O)
connector constructed in accordance with the principles of the
Present Invention;
[0019] FIG. 2 is the same view as FIG. 1, but showing the underside
thereof, and particularly illustrating the connector's capacitive
coupling contacts;
[0020] FIG. 3 is a bottom plan view of the I/O connector of FIG.
1;
[0021] FIG. 4 is a to plan view of the I/O connector of FIG. 1;
[0022] FIG. 5 is a front elevational view of the I/O connector of
FIG. 1;
[0023] FIG. 6 is a perspective view of a guide, or shell, mounted
to a printed circuit board and used in combination with the I/O
connector of FIG. 1, which directs the contacts of the I/O
connector into opposition with contacts on the circuit board;
[0024] FIG. 7A is the same view as FIG. 6, but with the I/O
connector of FIG. 1 partly engaged therewith;
[0025] FIG. 7B is the same view as FIG. 7A, but with the I/O
connector fully engaged with the outer shell;
[0026] FIG. 8 is an exploded view of the I/O connector and guide of
FIG. 7;
[0027] FIG. 9A is a perspective view of the I/O connector of FIG.
1, taken from the bottom and with the connector body removed from
its housing for clarity;
[0028] FIG. 9B is the same view as FIG. 9A, but in an exploded
format and with the direction of the I/O connector reversed;
[0029] FIG. 10 is a cross-section of the I/O connector of FIG. 1,
taken along Lines 10-10 thereof;
[0030] FIG. 11 is a cross-sectional view of the I/O connector of
FIG. 1 in alignment with and partly inserted into a guide mounted
on a circuit board;
[0031] FIG. 12 is the same view as FIG. 11, but with the I/O
connector fully mated with the contacts on the circuit board, such
view being taken generally along Lines 12-12 of FIG. 7;
[0032] FIG. 13 is a cross-sectional view of the shell of FIG. 14,
taken alone Lines A-A thereof and illustrating the plug connector
engagement members;
[0033] FIG. 14 is the same view as FIG. 13, but with the plug
connector of FIG. 1 inserted into the shell;
[0034] FIG. 14A is a cross-sectional view of FIG. 14 taken along
Lines A-A thereof and illustrating the interaction between the plug
connector wing members and the guide shell;
[0035] FIG. 14B is an enlarged detail view of FIG. 14, taken from
the bottom with the circuit board removed, and illustrating the
plug connector inserted into the guide shell;
[0036] FIG. 15 is a perspective view of the shell member of FIG. 6,
taken from underneath showing the press arms, mounting tabs and
positioning flanges;
[0037] FIG. 16 is a front elevational view of another embodiment of
a shell member used with the plug connectors of the Present
Invention;
[0038] FIG. 16A is a cross-sectional view of FIG. 16, taken along
Lines A-A thereof;
[0039] FIG. 16B is a bottom plan view of the shell member of FIG.
16; and
[0040] FIG. 16C is a rear elevational view of the shell member of
FIG. 16.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0041] While the Present Invention may be susceptible to embodiment
in different forms, there is shown in the Figures, and will be
described herein in detail, specific embodiments, with the
understanding that the disclosure is to be considered an
exemplification of the principles of the Present Invention, and is
not intended to limit the Present Invention to that as
illustrated.
[0042] The Present Invention relates to an I/O connector that
utilizes a capacitively-coupled mating interface. FIG. 1
illustrates a plug connector 100 constructed in accordance with the
principles of the Present Invention. The plug connector 100
includes an insulative housing 102 that is held within an exterior
shell 103. The shell may be either conductive so as to provide a
measure of electromagnetic shielding to the conductors (not shown)
of the plug connector, or it may be insulative. In either instance,
the exterior shell 103 provides a protective cover for the plug
connector housing 102. The shell 103 has a rear opening formed
therein that provides a pathway for electrical wires (not shown) to
enter and exit from the connector housing 102, within a protective
cable 106. The plug connector 100 is used to make electrical
contact between a plurality of wires disposed within a cable and a
series of contacts, preferably in the form of contact pads 152 that
are disposed on an opposing surface of a printed circuit board
153.
[0043] The connector housing 102 includes a mating portion 104 that
extends forwardly of the connector housing 102 and which takes the
form of an elongated mating blade 108 in the drawings. This mating
blade 108 has a top, or pressure, surface 110, a bottom, or contact
surface 112 and two opposing sides 114,116. As shown best in FIG.
2, the mating blade 108 may have a pair of wing members 120,122
which extend out from the side surfaces 114,116 and in doing so,
define a pair of notches 123,125 defined lengthwise between the
wing members 120,122 and the front edge 126 of the connector
housing 102 and the purpose of these wing members 123,125 will be
explained in greater detail to follow.
[0044] The connector housing 102 includes a plurality of conductors
130 that extend lengthwise along the housing 102. The conductors
130 are spaced apart from each other, widthwise of the housing 102
and each conductor 130 has a width W and the conductor 130 are
separated from each other by an intervening spacing D. The width
and spacing may be the same, or it may differ as shown in FIG.
3.
[0045] The mating blade 104 may be formed of the same material as
the connector housing 102, namely, an insulative resin or the like
and the conductors 130 may be formed in a variety of ways. Firstly,
the conductors 130 may include conventional conductive metal
contacts formed as terminals, and secondly the conductors 130 may
be formed in place on the connector housing 102 and mating blade
108 by application of a conductive plating thereof, or by molding
the connector housing 102 in a two-shot process with the conductors
being molded from a conductive plastic or other material. Also, the
conductors 130 may be formed by etching or laser treatment such as
LDS, or other methods and manners that are known in the art. It is
preferred that the conductors 130 be formed as part of the housing
by using conductive plating or plastic so as to obtain the benefit
of an overall reduced height and cost for the plug connector
100.
[0046] FIG. 9B is an exploded view of the plug connector 100, taken
from the underside thereof to better illustrate the mating and
terminating faces thereof. As shown, the connector housing 102 may
include a wall 134 that serves to define a barrier between the
mating blade 108 (or mating face 133) and the terminating face 136
of the plug connector 100. A series of channels, or slots 138, are
shown extending lengthwise between the ends of the connector
housing 102 and extending between the mating and terminating faces
133,136. Each channel 138 receives an elongated conductive 139
member that defines a single conductor 130. As stated above, the
conductive members 139 may be metal terminals or conductive
plastic, or they may represent an extent of conductive material
molded in place within the connector housing 102.
[0047] On the terminating face 133, or mating blade 108, the
exposed exterior surfaces 140 of the conductors 130 preferably lie
flush with the bottom surface 142 of the mating blade 108 so that
the mating blade will lie in reliable contact against the upper
surface of the circuit board 153. On the terminating face portion
136 of the connector housing 102, the exposed exterior surfaces 140
of the conductors 130 are recessed to form a terminating channel,
or nest 144, into which the exposed conductors 145 of cable wires
146 may be held. The exposed conductors 145 are preferably attached
to the connector housing conductors by way of soldering or the like
(FIG. 9A).
[0048] In an important aspect of the Present Invention, the plug
connector 100 utilizes a capacitively coupled mating interface,
rather than a traditional metal to metal (galvanic) mating
interface. As best shown in FIG. 9B, a thin dielectric film, or
layer 150, is applied to the exposed surfaces of the plug connector
conductors 130. This film, or layer 150, provides a non-galvanic
signal transmission medium that is interposed between the plug
connector conductors 130 and the contacts arranged on the surface
of the circuit board 153. Typically, a film will be used and the
dielectric may utilize a plastic, engineered or otherwise, on the
order of about 0.015 millimeters thick while in a layer form, the
dielectric member may be in the form of a coating that is formed by
printing, dipping, painting, sputtering or any other suitable
manner. Preferable materials have a high dielectric constant of 200
or more and preferably 300 although suitable results have been
obtained where the dielectric constant of the entire system has
been as low as about 45.
[0049] The target dielectric constant for connectors of the Present
Invention is 300 and this may be achieved either by using a
dielectric barrier with a dielectric constant of 300 and ensuring
that there is a sufficiently large contact force applied to the
conductors and the dielectric barrier (layer) to press the mating
blade dielectric barrier portions into intimate contact with the
circuit board contact pads so that there is hardly any air gap
remaining between the dielectric barriers and the contact pads 152
of the circuit board 153 when the plug connector is fully inserted
into the shell member 200. It has been found that the force
required to obtain such intimate contact is much less that that
required to effect a normal galvanic connection. For example, it
has been discovered that as little as 8.1 grams of force can
provide capacitively coupled connectors of the Present Invention
with a capacitance of 11.0 picofarads while a comparable galvanic
connector would require 30 grams of force for effective contact.
The contact force is an important consideration for it is desirable
to eliminate any air gap between the dielectric and the opposing
conductor that it is pressed against, for the sir gap affects the
effective dielectric constant of the two conductors and any
interposed dielectric, as well as the capacitance for the
assembly.
[0050] The dielectric constant will also affect the overall height
of the connector assembly in which a dielectric interposer is used.
When a dielectric interposer with a dielectric constant of 200 was
used, electrical signal transfer was accomplished using a contact
with dimensions of about 1.5 millimeters by about 4.0 millimeters
with a resulting thickness, or height, taken through the contact
and dielectric material of about 0.2 millimeters. However, when a
material with a dielectric constant of 300 was used, the contact
size could be reduced down to about 0.2 millimeters by about 1.5
millimeters and the thickness was reduced down to about 0.015
millimeters.
[0051] It has been found that metallic oxides provide a useful
dielectric constant and the oxides may be applied to the conductors
130 by way on individual application or enhanced oxidation. Two
such oxides that give desirable results are titanium and copper
oxide with other oxides being suitable, such as aluminum, chromium
and nickel oxides. Ceramic materials may also be used and are
suitable for coating application of application by way of thin
sheets of ceramic. It is preferred that the thickness of the
dielectric barrier 140 is less than the thickness of the plug
connector conductors 130 and thicknesses of the dielectric barrier
range from between about 20,000 nanometers (0.2 millimeters) and
300 nanometers (0.0003 millimeters) thick. Such dielectrics are
best applied in a coating manner, such as by sputtering.
[0052] The dimensions of the dielectric members are preferably the
same as the plug connector conductors or the circuit board contact
pads 152. In this regard, it is desired that the width and length
of the plug connector conductors be the same or slightly larger
than the circuit board contacts. Typically, the plug connector
conductors should not be greater than 110% of the dimensions and
size of the circuit board contact pads 152.
[0053] The plug connectors 100 of the Present Invention are
preferably used in conjunction with an exterior guide, or shell
member, 200 that is formed from a conductive material such as a
sheet metal, or a conductive material such as a plastic plated with
either with a conductive layer or otherwise rendered conductive
such as by entrainment of conductive particles therein, or the
exterior may include one or more conductive layers that are molded
in place within the member. The term shell is used herein to
describe a member that serves to guide and hold the plug connector
in place, rather than provide an exterior covering for the plug
connector as shell might be interpreted. Accordingly, as used in
this detailed description, the terms "shell" and "guide" are
intended to be synonymous.
[0054] The shell member 200 has a plurality of walls that
cooperatively define its shape. These include a top wall 201, two
side walls 202, 203, a rear wall 204 and a front extension wall 205
that extends from the two side walls 202, 203 underneath the top
wall 201, and along the front edge 154 of the circuit board 152 to
define an entrance, or passage 207 at the front end 206 of the
shell member 200. The mating blade 108 of the plug connector 100 is
received within this opening 207 and the plug connector mating
blade 108 preferably extends all the way into the shell member 200
close to or in contact with the shell member rear wall 204. In this
mating position, the mating blade conductors 130 and the dielectric
barriers 140 disposed thereupon will lie above and in opposition to
the circuit board contact pads 152. In order to mount the shell
member 200 to the circuit board 153, the shell member 200 may
include one or more mounting legs, in the form of flanges or tabs
210 that extend outwardly from the side walls 202, 203 thereof.
These tabs 210 may be attached to like ground or attachment pads
212 on the circuit board by way of soldering or the like. The
mounting flanges 210 may be positioned elsewhere on the shell
member 200. The mounting flanges 210 may be formed by way of slots
211 in the sidewalls 202, 203 that serve to define the dimensions
of the mounting flanges 210 and facilitate their bending in the
outwardly direction.
[0055] In order to effect the desired contact between the plug
connector conductors 130, the dielectric barriers 140 applied
thereto, and the circuit board contacts pads 153, the shell member
200 includes a means for exerting contact pressure onto the plug
connector mating blade 104. In the drawings, this pressure exerting
means is illustrated as a pair of press arms 220 that are disposed
in the top wall 201 of the shell member 200. These press arms 220
extend at a downward angle into the hollow interior portion of the
shell member 200. In instances where the shell member is formed
from a sheet metal or similar materials the press arms may be
stamped and then bent downwardly and in instances where the shell
member is made from a non-metal, such as molded form a plastic or
similar material, the press arms are molded in place at their
downward angle. In this manner, the press arms 220, especially the
free ends 221 thereof make contact with the top, pressure surface
110 of the mating blade 108 as it is inserted into the shell member
200. The sequence of insertion is shown best in the cross-sectional
views of FIGS. 10-12. The press arms 220 extend in a cantilevered
manner, lengthwise of the shell member 200 preferably with the free
ends 221 extending in a direction rearwardly thereof and located
nearer the shell member rear wall 204 than the front 206.
Preferably, the shell member 200 is formed from an elastic material
so the press arms 220 themselves will exhibit elastic properties
and exert a desired pressure on the plug connector mating blade
108, yet return to their original position when the mating blade
108 is removed from inside of the shell member 200.
[0056] In order to assist in properly positioning the plug
connector conductors 130 in alignment with the circuit board
contacts 152, the shell member 200 preferably includes a means for
orienting the conductors, and as shown in FIGS. 13-5, these means
may include a pair of engagement or positioning flanges 208 that
are turned inwardly along the bottom of the two side walls 202, 203
so that they extend into the hollow interior space of the shell
member 200. These engagement flanges 208 lie flush with the top
surface of the circuit board 153 and the plug connector 100 is
provided with a pair of engagement recesses, or notches 114, 116
that are disposed on the plug connector mating blade 108 adjacent
the connector housing 102. As shown best in FIG. 14B, these notches
114, 116 may be considered as defining wings 120, 122 at the
forward side ends of the mating blade 108. The notches 114, 116 of
the mating blade are forced down onto the circuit board in a manner
such that they abut the shell member engagement flanges 208,
specifically the mating blade trailing edges 2000 abut the trailing
edges 2002 of the engagement flanges 208. Likewise, the mating
blade wing portions 120, 122 are received in the space between the
front edge of the engagement flanges 208 and the shell member rear
wall 204.
[0057] As shown in FIG. 14, the engagement flanges 208 serve to
limit the forward and sideward movement of the mating blade 108
when it is fully inserted into the shell member 300. The engagement
flanges 208 and the press arms 220 then cooperate to retain the
plug connector 100 in place within the shell member 200, with the
press arms forcing the mating blade conductors 130 and their
dielectric barriers 140 down into contact with the circuit board
contacts 152. The engagement flanges 208 likewise define a pair of
slots within the shell member at the surface of the circuit board
163 into which the mating blade wing portions 120, 122 are received
in a manner such that proper mating of the plug connector 100 with
the shell member 200 is reliably effected. The engagement flanges
208, as shown in FIGS. 14 and 14B, serve to restrain the mating
blade 108 from excessive forward and sideward movement. In this
manner, the plug connector may be pushed in horizontally until its
wing portions 120, 122 fall into the slots defined between the
engagement flange 208 and the shell member near wall 204.
[0058] FIGS. 16-16C illustrates another embodiment of a connector
system constructed in accordance with the principles of the Present
Invention. In this embodiment, the shell member 300 has a sets of
contacts integrated with it. As shown in FIG. 16A, the shell member
300 includes a top wall 301, a bottom wall 302, a rear wall 303 and
two side walls 305, 306 and a front rim wall 304, all of which
cooperatively define a hollow interior space which receives the
mating blade of a plug connector (not shown) as described for the
other embodiments above. A pair of press arms 325 are formed in the
top wall 301 and they extend downwardly into the interior space,
and the shell member 300 also includes mounting flanges 308 for
attaching it to a circuit board. However, in this embodiment, the
bottom wall 302 may have conductive strips 310 applied to the
bottom surface thereof as shown in FIG. 16B and these conductive
strips may be spaced apart widthwise along the bottom wall 301 by
intervening non-conductive, dielectric areas 315. This is
accomplished in one instance by forming the shell member 300 out of
an insulative, but high dielectric material, such as a plastic or
resin and plating selected portions of the exterior with a
conductive plating. These portions would include the top wall 301,
rear wall 303, side walls 305, 306 and mounting flanges 308 so as
to provide a conductive shield over the exterior surfaces of the
shell member 300.
[0059] Similarly, the bottom wall 302 of the shell member 300 may
be selectively plated to define the aforementioned conductive
strips 310 and because the material of construction is a
dielectric, the bottom wall 302 may serves as a dielectric
interposer 315 between the plug connector conductors 130 and the
contacts 152 on the circuit board 153. The conductive strips 310 on
the bottom of the shell member 300 may be soldered or otherwise
attached to the circuit board contacts. The inner surface (i.e.,
the top surface of the bottom wall 302) of the bottom wall 302 of
the plug connector 100 may also be plated to define conductive
surfaces, or contacts, therein to provide a galvanic connection
between the plug connector (without any dielectric barriers
thereon) and the inner contacts of the shell member, while relying
upon the bottom wall of the shell member to provide the dielectric
signal transmission medium for the connector assembly.
[0060] In another alternative construction, the contacts of the
shell member may include conductive portions that extend completely
through the bottom wall and the dielectric signal transmission
barriers will include the dielectric barriers 140 applied to the
plug connector conductors 130.
[0061] The benefits of the Present Invention are multiple. It has
been found that the heights of such I/O connectors can be reduced
down to 1.55 millimeters and at least 1.0 millimeters is possible,
which represents a significant reduction in height over prior known
I/O connectors for similar applications of 3.0 millimeters and
higher. The use of high dielectric constant materials as the
interposed barriers results in reduced sizes being required for the
contacts. Additionally, because the conductors 130 are formed on
the bottom mating surface of the plug connector mating blade 108
and are preferably applied as a coating or layer, the use of a
contact beam as found on conventional metal terminals is eliminated
and along with it the concern of having a sufficient contact force.
The only force that need be exerted with connectors of the Present
Invention is a pressure force from the press arms of the shell
members, leading to more simplified mechanical construction, which
results in a reduction in the time and cost of manufacturing
connectors of the Present Invention.
[0062] While a preferred embodiment of the Present Invention is
shown and described, it is envisioned that those skilled in the art
may devise various modifications without departing from the spirit
and scope of the foregoing Description and the appended Claims.
* * * * *